Replace rate distortion sse skip by RD_STATS in rdopt.c

This CL doesn't change any coding behavior.
The functions modified in this CL include
choose_smallest_tx_size()
choose_largest_tx_size()
choose_tx_size_type_from_rd()
txfm_rd_in_plane()
txfm_yrd()

This change make the code cleaner and will facilitate rd_debug
implementation

Change-Id: I19b1b2384dce8b46b28d4c9baf80ff92998d05b6

av1/common/blockd.h

@@ -212,7 +212,10 @@ typedef struct {
 #endif  // CONFIG_FILTER_INTRA
 
 #if CONFIG_VAR_TX
+#if CONFIG_RD_DEBUG
 #define TXB_COEFF_COST_MAP_SIZE (2 * MAX_MIB_SIZE)
+#endif
+#endif
 
 // TODO(angiebird): Merge RD_COST and RD_STATS
 typedef struct RD_STATS {
@@ -226,7 +229,6 @@ typedef struct RD_STATS {
                         [TXB_COEFF_COST_MAP_SIZE];
 #endif
 } RD_STATS;
-#endif  // CONFIG_VAR_TX
 
 // This structure now relates to 8x8 block regions.
 typedef struct {

av1/encoder/rdopt.h

@@ -26,7 +26,6 @@ struct AV1_COMP;
 struct macroblock;
 struct RD_COST;
 
-#if CONFIG_VAR_TX
 static INLINE void av1_init_rd_stats(RD_STATS *rd_stats) {
 #if CONFIG_RD_DEBUG
   int plane;
@@ -90,7 +89,6 @@ static INLINE void av1_merge_rd_stats(RD_STATS *rd_stats_dst,
   }
 #endif
 }
-#endif
 
 int av1_cost_coeffs(const AV1_COMMON *const cm, MACROBLOCK *x, int plane,
                     int block, int coeff_ctx, TX_SIZE tx_size,